Description:Genus Description - Plants of small to medium or large size, whitish becoming light brown, or greenish-brown to dark brown, erect or ascending, radially symmetric, in tufts or cushions or among other bryophytes; stems simple or with an occasional branch, the branches lateral, of the Frullania type, with the half-leaf at the dorsal base of the branch; stem in transverse section with the cortical cells scarcely smaller than those of the medulla. Rhizoids when present in tufts from the lamina of the underleaves, the tips branched. Line of leaf insertion transverse or oblique, the leaves succubous. Leaves quadrate-orbicular to quadrate or rectangular, symmetric, quadrifid to one-half or four-fifths of their length, in some species with an additional large tooth or shorter segment on either side of the base of the lamina; margins with very numerous, long, spreading cilia, or the cilia shorter, two to four cells long, in a few opposite pairs on the segments and a few on the margins of the lamina, or entire; cuticle striolate. Underleaves like the leaves or slightly smaller. Plants dioicous. Male inflorescence terminal but becoming intercalary on the stem or branch, the bracts and bracteoles in four to ten series, a little larger than the leaves and underleaves, with more cilia; antheridia large, one or two in the axils of the bracts. Female inflorescence terminal on the stem or a long branch, without or with one or two subfloral innovations, the bracts and bracteoles similar and like the leaves and underleaves, with more cilia on the margins (in species with few or no cilia on the leaves, the margins of the bracts and bracteoles with numerous short cilia, the segments always with numerous pairs), the inner series the largest; archegonia ten to fifteen, flask-shaped with a narrow neck. Perianth long, cylindric, with three rounded keels above, without superficial paraphyllia, the mouth scarcely contracted, spinose to long-ciliate. Sporophyte seta in transverse section of a large number of cells, the outer layer of 18-20 large cells surrounding the numerous similar or smaller cells of the of the medulla; capsule ovoid-cylindric, reddish-brown, the wall of four to six layers of cells, the outermost layer of very large, hyaline cells, the inner layers of smaller cells with the characteristic brown, rod- or band-shaped thickenings; elaters reddish-brown, with two or three spirals, the ends blunt-tapering; spores reddish-brown.